Atrial Fibrillation: When the Electrical System Misfires (Video)

300 heartbeats per minute can be dangerous for some

Nearly 100 percent of arrhythmias, or irregular heartbeats, that occur take place in the atria, or the upper chambers of the heart. The most common ones that we hear about are atrial fibrillation and its cousin, atrial flutter. When this occurs, the heart’s electrical system misfires, causing the rapid firing of too many different impulses at once. This in turn, causes a very fast, chaotic rhythm in the atria.